IEA scenarios

Definition:

The International Energy Agency has
developped a number of scenarios that describe the efforts needed to reduce
carbon dioxide emissions. The "business-as-usual" Baseline scenario foreshadows
the situation in the absence of policy change and major supply constraints
leading to increases in oil demand and CO2 emissions.

Other scenarios explore different technological pathways to achieve emission
reductions, and, the "Energy technology perspectives" report groups the
scenarios into two main subgroups, depending on emission reduction objectives:

The "ACT" scenarios bring back CO2 emissions to
2005 levels by 2050 through a number of technological developpments.

The "BLUE" scenarios are more ambitious, bringing emissions
at 50% of the 2005 level by 2050. This implies of course higher investment
costs, but also greater needs in technological and policy developments.